Study on the Effect of Steel Slag in Improving Saline Soil

Saline soil is a special type of soil characterized by a high content of soluble salts and poor engineering properties. This study proposes the use of steel slag to improve saline soil and investigates the effects of different steel slag contents and curing ages on the mechanical properties of saline soil through unconfined compressive strength (UCS) tests, direct shear tests, and Atterberg limits tests. The results indicate that steel slag powder significantly enhances the mechanical properties of saline soil. UCS, stiffness, and cohesion increase with curing age, while they exhibit an initial increase followed by a decrease as the steel slag content rises. The optimal improvement effect is achieved at a steel slag content of 2.5% and a curing age of 28 days, with respective increases of 103.9%, 303.2%, and 162.4%. Additionally, the internal friction angle increases with steel slag content, with a maximum increment of 7.81°. The Atterberg limits test results show that steel slag powder increases the plastic limit of saline soil, whereas the liquid limit and plasticity index decrease with increasing steel slag content. In summary, steel slag exhibits excellent potential for improving the properties of saline soil.